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How to display stack?

Nov 12, 2013 at 12:45am
sethman410 (10)
Hello programmers. I am learning how to make stacks. The instructor wants me to display the stack after you enter the elements or pop them out. All the examples I have seen so far from the book and the internet haven't shown me how to display them. So, not really sure how to do this. Here's the code I got so far from the header file.

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#ifndef INTSTACK_H
#define INTSTACK_H
#include <iostream>
using namespace std;

class IntStack
{
private:
	int *stackArray;
	int stackSize;
	int top1;
	
public:
	IntStack(int);

	IntStack(const IntStack &);

	~IntStack();

	bool isEmpty();    // returns true if stack is empty
	bool isFull();     // return true if stack is full
	void push(int n);  // item n is pushed onto stack, throw exception on full stack.
	void pop(int &);   // removes top item from stack, throw exception on empty stack.
	int top();         // returns top of stack, throw exception on empty stack.
	void printStack(); // prints stack, stack is unchanged
};

IntStack::IntStack(int size)
{
	stackArray = new int[size];
	stackSize = size;
	top1 = -1;
}

IntStack::IntStack(const IntStack &obj)
{
	if (obj.stackSize > 0)
		stackArray = new int[obj.stackSize];
	else
		stackArray = NULL;

	stackSize = obj.stackSize;

	for (int count = 0; count < stackSize; count++)
		stackArray[count] = obj.stackArray[count];

	top1 = obj.top1;
}

IntStack::~IntStack()
{
	delete [] stackArray;
}

void IntStack::push(int num)
{
	if (isFull())
	{
		cout << "The stack is full.\n";
	}
	else
	{
		top1++;
		stackArray[top1] = num;
	}
}

void IntStack::pop(int &num)
{
	if (isEmpty())
	{
		cout << "The stack is empty.\n";
	}
	else
	{
		num = stackArray[top1];
		top1--;
	}
}

bool IntStack::isFull()
{
	bool status;
	
	if (top1 == stackSize - 1)
		status = true;
	else
		status = false;

	return status;
}

bool IntStack::isEmpty()
{
	bool status;

	if (top1 = -1)
		status = true;
	else
		status = false;

	return status;
}
#endif


As you can see, I have the operation called printStack(). The question is how do you code this operation?

I was thinking about using the for loop and somehow code it that way. Not sure how to do this.
Nov 12, 2013 at 12:54am
long double main (999)
It's just like what you did on lines 44 and 45, except you print the elements instead of assigning values to them.
Nov 12, 2013 at 1:43am
sethman410 (10)
This is my program output. Why is it doing that?



What do you want to do?
1 - Push an item onto the stack
2 - Pop an item off the stack
3 - Quit the program
Enter your choice: 1

Enter an item: 1
11-842150451-842150451-842150451-842150451-842150451-842150451-842150451-8421504
51-842150451-842150451-842150451-842150451-842150451-842150451
What do you want to do?
1 - Push an item onto the stack
2 - Pop an item off the stack
3 - Quit the program
Enter your choice: 1

Enter an item: 2
212-842150451-842150451-842150451-842150451-842150451-842150451-842150451-842150
451-842150451-842150451-842150451-842150451-842150451
What do you want to do?
1 - Push an item onto the stack
2 - Pop an item off the stack
3 - Quit the program
Enter your choice: 1

Enter an item: 1
1121-842150451-842150451-842150451-842150451-842150451-842150451-842150451-84215
0451-842150451-842150451-842150451-842150451
What do you want to do?
1 - Push an item onto the stack
2 - Pop an item off the stack
3 - Quit the program
Enter your choice: 2
The stack is empty.
121-842150451-842150451-842150451-842150451-842150451-842150451-842150451-842150
451-842150451-842150451-842150451-842150451
What do you want to do?
1 - Push an item onto the stack
2 - Pop an item off the stack
3 - Quit the program
Enter your choice: 1

Enter an item: 3
3321-842150451-842150451-842150451-842150451-842150451-842150451-842150451-84215
0451-842150451-842150451-842150451-842150451
What do you want to do?
1 - Push an item onto the stack
2 - Pop an item off the stack
3 - Quit the program
Enter your choice: 3
Press any key to continue . . .


Here's my code for header file.

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#ifndef INTSTACK_H
#define INTSTACK_H
#include <iostream>
using namespace std;

class IntStack
{
private:
	int *stackArray;
	int stackSize;
	int top1;
	
public:
	IntStack(int);

	IntStack(const IntStack &);

	~IntStack();

	bool isEmpty();    // returns true if stack is empty
	bool isFull();     // return true if stack is full
	void push(int n);  // item n is pushed onto stack, throw exception on full stack.
	void pop(int &);   // removes top item from stack, throw exception on empty stack.
	int top();         // returns top of stack, throw exception on empty stack.
	void printStack(); // prints stack, stack is unchanged
};



IntStack::IntStack(int size)
{
	stackArray = new int[size];
	stackSize = size;
	top1 = -1;
}

IntStack::IntStack(const IntStack &obj)
{
	if (obj.stackSize > 0)
		stackArray = new int[obj.stackSize];
	else
		stackArray = NULL;

	stackSize = obj.stackSize;

	for (int count = 0; count < stackSize; count++)
		stackArray[count] = obj.stackArray[count];

	top1 = obj.top1;
}

IntStack::~IntStack()
{
	delete [] stackArray;
}

void IntStack::push(int num)
{
	if (isFull())
	{
		cout << "The stack is full.\n";
	}
	else
	{
		top1++;
		stackArray[top1] = num;
	}
}

void IntStack::pop(int &num)
{
	if (isEmpty())
	{
		cout << "The stack is empty.\n";
	}
	else
	{
		num = stackArray[top1];
		top1--;
	}
}

bool IntStack::isFull()
{
	bool status;
	
	if (top1 == stackSize - 1)
		status = true;
	else
		status = false;

	return status;
}

bool IntStack::isEmpty()
{
	bool status;

	if (top1 = -1)
		status = true;
	else
		status = false;

	return status;
}

void IntStack::printStack()
{
	for (int count = 0; count < stackSize; count++)
		cout << stackArray[count];
}
#endif


This one is the main file.

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#include <iostream>
#include <string>
#include "IntStack.h"
using namespace std;

int item;

const int PUSH_CHOICE = 1,
		  POP_CHOICE = 2,
		  QUIT_CHOICE = 3;

void menu(int &);

int main()
{
	IntStack stack(15);

	int choice;

	do
	{
		menu(choice);

		if (choice != QUIT_CHOICE)
		{
			switch (choice)
			{
			case PUSH_CHOICE:
				 cout << "\nEnter an item: ";
				 cin >> item;
				 cout << item;
				 stack.push(item);
				 break;
			case POP_CHOICE:
				 stack.pop(item);
			}
			stack.printStack();
		}
	} while (choice != QUIT_CHOICE);


	system("pause");
	return 0;
}

void menu(int &choice)
{
		cout << "\nWhat do you want to do?\n"
			 << PUSH_CHOICE
			 << " - Push an item onto the stack\n"
			 << POP_CHOICE
			 << " - Pop an item off the stack\n"
			 << QUIT_CHOICE
			 << " - Quit the program\n"
			 << "Enter your choice: ";
		cin >> choice;

		while (choice < PUSH_CHOICE || choice > QUIT_CHOICE)
		{
			cout << "Enter a valid choice: ";
			cin >> choice;
		}
}
Edit & run on cpp.sh
Nov 12, 2013 at 2:17am
closed account (D80DSL3A)
What is the top1 variable for?
Why line 31 in main() function?
Last edited on Nov 12, 2013 at 2:18am
Nov 12, 2013 at 5:06am
sethman410 (10)
Oops. I don't think I wanted to put that there. What I had in mind was to display the stack but I am supposed to do that with printStack(). Taking that out.

top1 is the top of the stack.

The instructor specified that I need top() operation so it wouldn't let me to use "top" variable. So, instead, I put the 1 at the end so that way it doesn't act like it's trying to use the top() operation. Otherwise, I would get an error.

EDIT: Took "cout << item" out and still have the same results. Help!

I don't think I am properly coding the printStack() operation correctly. I think that is the source of the problem.
Last edited on Nov 12, 2013 at 5:18am
Nov 12, 2013 at 6:28am
closed account (D80DSL3A)
Good reply, but I asked about top1 because it's the key to the output problem. You are outputting all stackSize elements when only top1+1 elements should be displayed.
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